fix: Light-Theme-Hintergrund auf PWA/Android reparieren

Der hardcodierte Inline-Style auf body überschrieb --app-body-bg und ließ
hellen Modus mit dunklem Seitenhintergrund erscheinen. Theme-Bootstrap und
dynamisches theme-color ergänzen alle Scheme/Theme-Kombinationen.

Co-authored-by: Cursor <cursoragent@cursor.com>

client/src/services/appearance.test.ts

@@ -0,0 +1,70 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import {
+  applyAppearanceToDocument,
+  resolveAppTheme,
+  resolveColorScheme,
+  type AppTheme,
+  type ResolvedColorScheme
+} from './appearance.js'
+import { setColorSchemePreference } from './userPreferences.js'
+
+const USER_ID = 'appearance-test-user'
+
+const COMBOS: Array<{ theme: AppTheme; scheme: ResolvedColorScheme }> = [
+  { theme: 'ocean', scheme: 'dark' },
+  { theme: 'ocean', scheme: 'light' },
+  { theme: 'material', scheme: 'dark' },
+  { theme: 'material', scheme: 'light' },
+  { theme: 'cupertino', scheme: 'dark' },
+  { theme: 'cupertino', scheme: 'light' }
+]
+
+describe('appearance', () => {
+  beforeEach(() => {
+    localStorage.clear()
+    document.documentElement.className = ''
+    document.documentElement.style.colorScheme = ''
+    document.head.querySelector('meta[name="theme-color"]')?.remove()
+  })
+
+  it.each(COMBOS)('applies $theme · $scheme classes to document', ({ theme, scheme }) => {
+    applyAppearanceToDocument(theme, scheme)
+
+    const root = document.documentElement
+    expect(root.classList.contains(`theme-${theme}`)).toBe(true)
+    expect(root.classList.contains(`scheme-${scheme}`)).toBe(true)
+    expect(root.style.colorScheme).toBe(scheme)
+  })
+
+  it('replaces previous theme classes when switching appearance', () => {
+    applyAppearanceToDocument('ocean', 'dark')
+    applyAppearanceToDocument('material', 'light')
+
+    const root = document.documentElement
+    expect(root.classList.contains('theme-material')).toBe(true)
+    expect(root.classList.contains('theme-ocean')).toBe(false)
+    expect(root.classList.contains('scheme-light')).toBe(true)
+    expect(root.classList.contains('scheme-dark')).toBe(false)
+  })
+
+  it('resolves stored light scheme even when system prefers dark', () => {
+    vi.stubGlobal(
+      'matchMedia',
+      vi.fn().mockReturnValue({ matches: true, addEventListener: vi.fn(), removeEventListener: vi.fn() })
+    )
+    localStorage.setItem('active_userid', USER_ID)
+    setColorSchemePreference(USER_ID, 'light')
+
+    expect(resolveColorScheme()).toBe('light')
+    applyAppearanceToDocument('material', resolveColorScheme())
+    expect(document.documentElement.classList.contains('scheme-light')).toBe(true)
+  })
+
+  it('auto theme picks material on Android user agent', () => {
+    vi.stubGlobal('navigator', {
+      ...navigator,
+      userAgent: 'Mozilla/5.0 (Linux; Android 14) AppleWebKit/537.36'
+    })
+    expect(resolveAppTheme()).toBe('material')
+  })
+})

client/src/services/appearance.ts

@@ -31,6 +31,18 @@ export function resolveAppTheme(): AppTheme {
   return 'ocean'
 }
 
+function updateThemeColorMeta(root: HTMLElement): void {
+  const color = getComputedStyle(root).getPropertyValue('--app-theme-color').trim()
+  if (!color) return
+  let meta = document.querySelector('meta[name="theme-color"]')
+  if (!meta) {
+    meta = document.createElement('meta')
+    meta.setAttribute('name', 'theme-color')
+    document.head.appendChild(meta)
+  }
+  meta.setAttribute('content', color)
+}
+
 export function applyAppearanceToDocument(
   theme: AppTheme = resolveAppTheme(),
   scheme: ResolvedColorScheme = resolveColorScheme()
@@ -39,6 +51,7 @@ export function applyAppearanceToDocument(
   root.classList.remove(...THEME_CLASSES, ...SCHEME_CLASSES)
   root.classList.add(`theme-${theme}`, `scheme-${scheme}`)
   root.style.colorScheme = scheme
+  updateThemeColorMeta(root)
 }
 
 export function subscribeToSystemColorScheme(onChange: () => void): () => void {